Production of polyurethanes by a continuous process



Patented Nov. 10, 195 3 PRODUCTION OF POLYURETHANES BY A V CONTINUOUS PROCESS I Jack Swerdloif, Bloomfield; and Samuel B. McFarlane, Summit, N. J assignors to Celanese Corporation of America, New York, N. Y., a corporation of Delaware No Drawing. Application October 6, 1951, Serial No. 250,187

12 Claims. (Cl. 260-775) This invention relates to the production of polyurethanes and relates more particularly to a continuous process for the production of polyurethanes by the reaction of a, polyamine and a bis-chloroformate.

This-application is a continuation-in-part of our application S. No. 119,772, filed October 5, 1949, now abandoned.

An object of this invention is to provide a continuous process for the production of polyurethanes in high yield and of a molecular weight or chain length adapted for the production of commercially acceptable yarns, filaments and molded materials by suitable shaping operations.

Another object of this invention is the provision of a process for the production of polyurethanes involving the continuous reaction of an aqueous solution of a polyamine and an organic solvent solution of a bis-chloroformate whereby the continuous production of long chain polyurethanes may be effected. r

A further object of this invention is to carry out said continuous polymerization reaction in an emulsion form whereby substantially complete reaction of the intermediates is achieved-and a maximum yield of polyurethane is obtained. Yet another object of this invention is-the production of mixed polyurethanes by a process involving the continuous reaction of an aqueous solution of one or more polyamines with an organic solvent solution of one or more bis-chloroformates. 1

I A stillfurther object of this invention is the continuous production of pigmented polyuretha'nes wherein pigmentation is efiected simultaneously with thepolymerization of a polyamine and a bis-chloroformate.

Other objects of this invention will appear from the following detailed description and claims. H Thereaction of a polyamine and a bis-chloroifor-mateto produce a polyurethanehas previously been effected by mixing the said two substances in the presence of an alkaline agent" on a batch basis. The solid polymer which forms] as the reaction proceeds is separated from'the reaction medium and is then purified by a suitable washing procedure. This batch process not only sufiers from the well known limitations of all batch processes; but yields a mixture of 'polyurethanes of'widely difierent molecular weights.

One cause tending to produce a mixture of polyurethanes of diiferent molecular weights is the tendency of the alkaline agent, which isfadded:

eih reae on me u to neutralize t ehydrochloric acid liberated during the polymerization, to producera relatively rapid hydrolysis of the chloroformate group. The half hydrolysis of a bis-chloroformate produces a large number of socalled chain stoppers which, when they react with a growing polymer chain, will prevent a further growth of said chain. A similar interrup will make the purification thereof more difiicult;

These difficulties become especially serious when the production of the polymer is carried'out on a batch basis on a scale adequate for com mercial production. r

We have now found that the pr'oduction of polyurethanes by the reaction ofaa polyamine with a bis-chloroformate'may be efiected by a continuous process in such manner that the hydrolysis of the .bis-chloroformate is reduced to relatively unimportant amounts and highyields of polyurethanevpolymerof high'and relatively uniform molecular weight. may be readily obtained. In accordancewith our novel process, an aqueous solution. ofthe lpolyamine, an organic. solvent solution of the bis-chloroformate andan alkaline agent are introduced simultaneously and continuously intoa reactionlzone of relatively. restricted volume wherein. they are subjectedto strong agitation so: as to efiectathorough ad-w mixture and emulsification of the reactants: The W agitation shouldbe adequate to. effect a substantially complete.polymerization-during thei period; in which the polyamine. and 'bis-chloroformate pass through the'reaction 'zonemPrefer ably, to assist in the emulsification, there is a'lso introduced intothe reaction zone an emulsifying agent; In the reactionv zone, a rapid reaction takes place between the polyamine and thelbis-i chloroformate with'theproductionof a highiyield'.

.of finely divided, solidpolyurethane. ofhi gh 'and relatively uniform molecular weight; Generally, the reactants should pass; through thefrea'ction zone in a period oflessthanaboutjw minutes 01'.

- preferably in.;a period of from1 about 0.3 'to 3J0v minutes. The solid polyurethane is continuously ;r.emoved fromthe reactionf zone in the fof'rm of a slurry at the same volumetric rate as the solutions are introduced into the reaction zone and may be recovered from the reaction medium in any suitable manner such as filtration, decantation, centrifuging, on the like. Due to the rapidity with which the reactiontakes place and the relatively small volume of materials in the reaction zone, there is little opportunity for any appreciable hydrolysis of thebis-chloroformate to occur so that the difliculties' referred to above as resulting from the hydrolysis of the bis-chloroformate are substantially avoid. ed. In addition, because of the relatively small volume of the reaction zone, a high'degree or emulsification of the reactants may be readily attained so that the reactants will be, brought, into contact with each other very rapidly. V

The temperature of the solutions undergoing polymerization is advantageously maintained at from about to 25 C. or 35 C. to obtain the maximum yield of polymer of high molecular weight. However, lower temperatures down. to about 'l0- C. or even lower may also be employed by adding a suitable antifreeze agent such as methanol, ethylene glycol, glycerine, acetoneor dioxane to. the aqueous polyamine solution and employing an organic solvent having a freezing point below the temperature at which the polymerization is. carried out for forming the hischloroformate: solution. Higher temperatures may. also be employed forcarrying out the polymerization, but are somewhat less desirable in that they resultin a lower yield: of polymer having a lower and less uniform molecular weight.

Therateof flowof the aqueous polyamine solution. and the. organic. solvent bis-chloroformate solution through the reaction zone will depend in large part upon the efficiency with which said solutions arev stirred in said zone. For example, with a. reaction zone; having a volume ofabout 7;3;2 cubic-.inchesandiequipped with an air stirrer driven at. 4100 R. P. M., substantially complete polymerization may be achieved when a total of from about. .38. to 23'. volumes of solution are passed through thereaction zone per minute per volumeofi free reactor space. With more-efficient stirring, up. to.3.5-toreven more, total. volumes of solution may bepassed. through the reactionzone:

uenminutepen volume of 'free reactor space. The volumes-.01; solution passing through the reaction zonamay. include a, small: volume of: water which; serves; to dilute the slurry formed in. the

euent thatamechanical'.diflicultiesare encountered in. handling the same. The aqueous. polyamine solution? and. the organic solvent bis-chloro-. formate solution should, in general, have a high concentration to-reduce to a minimum the volumeof. material: that must be handled for the produc tion of: a. given amount of polyurethane: The concentrationof:thesolutionsis, however, limited: by the mechanical-problems. involved in handling the. polymer slurrywhich is. formed; For example with. theireaction zone specified: above: and; employing aisiphontubetfi inches indiam eter operating; under a. head: ofi8 /zinches, solu-v tions, having. a concentration of between about- 0.2 and; 1:.0; moles per liter of reactants. have proved: satisfactory; Withmore efficient and more ipositive: slurryi handling means; such as pumps and the like, solutions having a concentration; ofs up to.about 1.5, or even more, molesper literof reactants may be employed. It is preferred, for reasons of# economy to employsub tantially equir'nolecular amounts. of the poly-- amine and bisrchlurofnrmate. 'Ihisnis not-- es bis-chloroformate, there may be employed a wide variety of water-immiscible solvents. Suitable materials for this purpose include benzene, toluene, xylene, chloroform, carbon tetrachloride, octane, naphthenev and the hydrocarbon mixture of aromatics, paraifins and naphthalenes sold under the name Varsol. Aromatic solvents, particularly toluene, are preferred for this purpose since they yield a maximum yield of polymer of the desired molecular weight.

During the polymerization reaction, hydrochloric acid is liberated and reacts with the alkaline agent that is introduced into. the. reaction zone together with the polyamine andv the bischloroformate. Preferably, the. alkaline agent is; employed in excess of that required exactly to neutralize all of the hydrochloric acid; formed. Depending upon the specific alkaline agent, the optimum resultswith regard to yield are obtained with a molar excess of up to about For example, when sodium hydroxide is. employed as the alkaline agent, the molar excessshould pref.- erably rangefrom aboutIO. to When sodium carbonate is the alkaline agent, the molar. excess: should; preferably range from about, 10; to; 75%.. Suitable alkalme-agents-that may be employed, addition to sodium hydroxide and sodium: carbonate, are an excess of thepolyaminaitself', the: soluble alkalimetalor alkaline earth meta-loxidea. hydroxides and carbonates, such as potassium; hydroxide, barium hydroxide, disodium. phos phate, and trisodium. phosphate, quaternary. armmonium bases and the like. The, alkaline. agent may be dissolved; in: the aqueouspolyamine solution; before the latter is introduced. into the IE? action. zone, or; itzmaybe introduced into the re:- act-ion: zonein the-formof aseparatesolution;

Various, types, of emulsifying: agents. may be: introducedzinto, the reaction zone, eitherin solution; with: one of, the; reactants or separately; to: assist-in: effcctingiauniiorm; and rapidwmulsificax. tion of. thereactantsolutions. Examples ofsuite able; emulsifying; agents are; ethylene; oxide cont-- densates with long chain fatty alcohols, estersaofi sodium sulfosuccinicj acid suchas. the dioctyl ester, long chain; fatty acid esters of polyethylene: glycol, ethyleneoxide-condensates with castonoil; long;v chain monoglycerides, alkyl: aryl; polyether: alcohols, e. g. the reaction'product; of; ethylene: oxide; andxylenol, sorbitan monolaurate;. the condensation: product; p of sorbitanr monolauratei with ethylene oxide, monoor poly-alkyl naphe thalene, sulfonates sulfates of, fatty acid. monoglyoerides .or the;glycolesters of long chain fatty acids. It is. important',,for-: the; production ofv polymersof goodnol'or, thatthe emulsifying-,agentr be-asqf'ree as possible of colored bodies as; the: polymer tends to I scavenge .1 coloredbodies from: the emulsifying; agent and. the reaction: mixture; The-most advantageous results are'obtained; how'- ever,by=employing emulsifying agents comprising: the' sodium salts-.ofrsulfated long: chain alcohols such: as sodium lauryl sulfate, sodium octy-l sul-- fate, sodium oleyl sulfate andthe like: Gtiier emulsifying agents that maybe employed include thesodium S3 6 of an N substltuted aminoethane-sulfonio acid} i. ea an it-substituted 5, taurine.- The substituents on the nitrogen may include bothalkyl groups, such as methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, ,octyl, decyl, undecyl, dodecyl, etc., and acidyl groups. The acidyl group, when present, is preferably the acidyl group of a long chain saturated or unsaturated aliphatic acid containing six to eighteen carbon atoms. Examples of said acids are lauric, oleic, ricinoleic, linoleic, caproic, pimelic, heptylic, undecylic and stearic acid. Good results are achieved by employing the sodium salt of N- butyl, N -lauroyl-p-amino-ethane sulfonic acid as the emulsifying agent. The amount of emulsifying agent employed is preferably from about 4.5 to 10.5 grams/gram mole of reactants on a 100% strength basis.

Examples of diamines which may be employed in forming polyurethanes in accordance with the novel polymerization process of our invention are ethylene diamine, trirnethylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, orthometaor paraphenylene diamine, cyclohexylene diamine and nuclearly substituted-phenylene diamines and nuclearly substituted-cyclohexylene diamines. N-substituted diamines which contain a free amino hydrogen on each amino group are also suitable.

Other diamines which may also be employed are, for example, a,w-di-(3-aminopropoxy)-alkanes, such as 1,4-di-(3-aminopropoxy)-butane, bis-(w-amino-alkyl) ethers such as 3,3- diaminedi-propyl-ether, 4,4'-diamino-dicyclohexyl methane, bis-(w-amino-alkyl) sulfides such as 2,2- diamino-di-ethyl-sulfide, 1,2-, 1,3- or 1,4-a,a.'- diamino xylene or other w,w'-diamino-dialkyl benzene, diamino-naphthalene, diamino-biphenyl, w,w-diamino-dialkyl biphenyls, u-amino-alkyl anilines, w-amino-alkyl cyclohexylamines, bis-(w amino-alkoxy) -benzene, bis- (w-amino-alkoxy) cyclohexane; 4,4-diamino-dicyclohexyl sulfones, w,w'-sulfonyl-bis-alkyl amines, diamino-diphenyl sulfones, diamino-benzophenones and N,N-bis- (w amino alkyl) a,w alkane disulfonamides. Amines containing more than two reactive amino groups, either primary or secondary, such as diethylene triamine or triethylene tetramine, for example, yield branch chain polyurethanes. Such polymers, if they contain moderately branched chains, are of relatively low melting point. If the chains are highly branched the polymers approach and may even reach substantial infusibility.

The bis-chloroformates which are reacted with the above mentioned diamines may be obtained by reacting phosgene, i. e. carbonyl chloride, with a diol. The bis-chloroformates of diols such as ethylene glycol, trimethylene glycol and 1,4- butanediol, for example, are suitable. Higher glycols wherein the alkylene chain contains a greater number of carbon atoms and may be a straight chain or a branched chain are also satisfactory. Examples of other diols whose bischloroformates may be employed are w,w'-dihydroxyl-dialkyl ethers, w,w'-dihydroxy-dialkyl thioethers, bis-glycol or diglycol esters of straight chain or branched chain aliphatic dicarboxylic acids such as the bis-ethylene glycol ester of succinic acid, the bis-diethylene glycol ester of succinic acid, the bis-ethylene glycol ester of glutaric acid, the bis-ethylene glycol ester of adipic acid; the bis-ethylene glycol ester of pimelic acid, the

bis-ethylene glycol ester of suberic acid, azelaic acid or sebacic acid, the diol, dimer or trimer esters obtained b the conversion.qtanexcessoi an aliphatic 'glycol'with a di carboxylic acid of the several aliphatic dicarboxylic acids mentioned above, w,w'-dihydroxy-dialkyl ethers of hydroquinone, w,w'-dihydroxy dialkyl ethers of di-hydroxy cyclohexane, w,w'-sulfonyl bis-alkanols, i. ebis- (w-hydroxyalkyl-sulfones) N ,N (w-hYdl'OXY- alkyD-dicarboxyamides such as N,N'-(,B,,9'-di-- hydroxy-diethyl)-adipamide, cycloaliphatic gly-- cols as cyclohexylene glycol, dihydroxy tetrahydrofurane, hydroxy-hydroxymethyl furane, hydroxy-hydroxymethyltetrahydrofurane, and dihydroxy oxathiane dioxide. 7

Thus, the polyurethane may contain an al-' kylene linkage of two, three, four, five or more carbon atoms alternating with an alkylene linkage of two, three, four, five or more carbon atoms. For ready identification, the alkylene polyurethanes may be identified as 2,4-, 3,4-, 4,4-, 5,6-, 6,6-, etc. polyurethanes, the former numeral referring to the carbon chain length of the-diamine employed while the latter refers chain length of the bis-chloroformate. polyurethanes containing any type of mediate linkage or grouping as brought out above may. also be formed by employing any of the diamines and bis-chloroformate of the diols mentioned or a mixture of two or more diamines or two or more different bis-chloro-- formates.

Pigmented polyurethanes may be readily ob-; tained by introducing continuously into the reaction zone a slurry or dispersion of a suitable pig ment such as titanium dioxide,-Franconia blue, Opaline green, or Carlon black.

In order further to illustrate our invention, but without being limited thereto,the following examples are given:

Mixed inter- Example I 35.2 parts by weight of are dissolved in 1000 parts by weight of water containing 63.6 parts by weight of sodium carbonate (50% mol excess) and 6 of sodium lauryl sulfate (30 by weight of 1,4-butanediol bis-chloroformate are dissolved in 900 parts by weight of toluene and both solutions separately cooled to a temperature of 20 C. The cooled'solutions are then simultaneously introduced into a reaction zone having 500 volumes'of free reactor space and provided with means to eifect strong agitation, such as a high speed stirrer, the aqueous solution being in troduced into the reactor at a per minute and the toluene troduced' at a rate of 87' volumes per minute.

Polymerization with the formation of LA-polyurethane takes place immediately as the separate solutions are brought together. The polymer formed precipitates fromsolution. The resulting 7 reaction. mixture containing the suspended polymer is withdrawn "from the reaction zone at the same rateat which thefresh solutions 'are"in'- troduced, the polymer separated by filtration,

washed-with acetone and'water to remove oc-'-" cluded solvent and inorganic salts and dried. The yield of 4,4-polyurethane polymer obtained is of theory and the an intrinsic viscosity of 1.29. 7

Example 11' 35.2 parts by weightv of tetramethylene diamine parts by weight of water are dissolved in 1000. containing 53 parts by weight of sodium carbonate and 16 parts. by weightof .sodium alkyl naph- 86.8 parts by weight. of .1,4:butanediol:bisechloroformate. arethalene sulfonate (30%. strength).

to the carbon.

different,

tetramethylene diamine parts by weightstrength). 86parts rate of 80 volumes solution being in-' polymer thus formed has dissoivedin 90o parts-by weight of mineral spirits comprising a mixture of petroleum hydrocarbons boiling within the range of. 300 to 410 F. and sold commercialLv-underthe name of Varsol #1 and both solutions separately cooled .to a temperature of 20 C. The cooled solutions are then introduced simultaneously, and with. strong agitation, into a reaction zone having 500 volumes of free. reactor space, the amine solution. being introduced at a rate of MQvoIumesper' minute and the 1Arbutanediol-bis-chloroformate solution. at a rate of volumes pei: minute. A. yield of 85%. ct a fllament-iorming. polymer having an; intrinsic viscosity of 1.26isobtained- Example III 35.2 parts-byweight 0t tetramethylene-di'amihe are: dissolved 1000 parts by weight of water containing 702 parts by weight of sodium car Donate (60% mol excess) and 35parts' by weight of sodiumla'uryl sulfate (30 strength). 103.2 parts by weight oflA-butanediolbis chlorofor mateare' dissolved in 900 parts by weight of toluene-andboth solutions then separately cooled to C; The cooled solutions are then simul'-- taneously introduced into a reactor having 500 volumes oi free reactor spaceandprovided withmeans forstirringat high speed; The diamine solution is introduced into the reactor at a rate ot'150-volumes per minuteand' thebis-chloroformate" solution at a ratecf 155 volumes per' minute. A'yield offilament formingpolymer of 88%- is obtained having' an intrinsic viscosity of 0.93.

Example IV 88 parts by weight of tetrametliylene" diamine' (1.0 mol) are dissolved in 1000 parts by weight of water containing 159-partsby weight of sodiumcarbonate1 (50.%;mol excess) and 'parts..by weight of a sodium lauryl. sulfate emulsifying agent (30% strength); 215 parts by weight of l-,4-butanediol bis chloroformateiare dissolvedin 9400 parts by, weight of toluene andboth solutions separately cooled toza-temperature of 20 C. The: cooled solutions are: thensimultaneously "intro"- duced-into a: reactionizonehaving 500 v'olumestof free reactor space. andprovided with means; such as ahigh-speed-stirrer; so as to effect. strong? agitation, the aqueous; solution being. introduced; intothe .reactor at a rate of 80 volumes per minute and the toluene-solution: being;- introduced atarate of 8'7 volumes-perminute. Polymeriza tion with: the; formation of. a IA-polyurethane? takesplace immediately as the separate: solutions? are brought together andvthe'rpolymer form'edi precipitates from solution. The resulting reac:- tion mixture: is withdrawn from the reaction; zone atthe samerateat which thefresh .solu. tions are introduced, the polymer separated: by filtrationr washed with water to remove: occluded inorganic salts and dried. The yield of 4-,4-polyurethaneis 87%.of theory and. the polymerisfound tohave an intrinsic viscosity of 1.45.

Example V 88 parts-by- -weight--.o tetramethylene' di'amine: are dissolved in 1000parts2by.weight .ofiwater containing 160 parts by, weight of sodium carbonate and parts by weight of sodium lauryl sulfate .;(30% istirength'). 21-5 parts by weight i of 1, i-butanedi0llbis-chloroformate are :dissolved iri 900:, partssrbyaweight 10f. toluene and both sold tions; are :separately cooled' to a temperature of; 3 20b 63;. Thc1ooo1ed solutions are then: introduced-' into ae.r l'eactor. -'having-.agitating means and-con 75s taming 500 volumes of free reactor space, the solutions each being addedat a rate of volumes per minute. The reaction mixture formed is thoroughly agitated in the reaction zone and is withdrawn, together with the polymer formed, at a rate equal to that at which solutions are introduced. The polymer formed is obtained in a yield of 81% of theory and has an intrinsic viscosity of 1.67.

Emample'VI npoiyurethanepoiymer is formed in the man ner described in Example V employing, however; a mineral Spirits solvent, Varsol #1, in lieu of toluene. The polymer formed is obtained in a yield of 83% of theory. The polymer has an intrinsic viscosity of 1.08.

Example VII 79'parts by weight of a commercial 76% aqueous solution of ethylene diamine is dissolved in 981 parts by weight or water containing parts by weight of sodium carbonate (50% mol excess) and 30 parts by weight of sodium lauryl sulfate (50% strength). 215 parts by weight of lxl-butane'diol' bis-chloroformate are dissolved in 900 parts by weight of toluene. The solutions are cooledseparatelyto 20 C. and introduced simultaneously into a-stirrer-equipped reactor'havin'g 500' volumes of free reactor" space, the diamine solution being introduced at a rate of 80 volumes per minute and the bis-chlordforniate solution at a rate of 87 volumes per minute. The agitated reaction product mixture is withdrawn from the reactor at the same rate at which the solutions are'introduced. The polymer formed is'obt'ained in a yield of 82% of theory an'd'has an intrinsic viscosity of 1.01;

Example VIII- 59;6'parts by weight of a 76% aqueous solution of ethylene diamine and 22 parts by weight of tetramethylene diamine are dissolved in 986 parts by weight of water'containinglfio parts by weight of sodium carbonate (50% mol excess) and 30 parts by weight of sodium lauryl sulfate (30% strength). 215 parts by weight of L l-butanediol bis-chloroformate are dissolved in 900" parts by weight of toluene and, after cooling both solutions toZO CI theyare simultaneously introduced into a reactor equipped with a stirrer and hai ingv 500 volumes of' free reactor space. The di'aininc solution is introduced at'a rate of '80 volumes per minute and the bis-chloroformate solution introduced at a rate of 87 volumes per minute.- The reaction mixture containing the polymer formed is withdrawn from the reactor at the samer'ate at which the combined solutions are introduced: The polyfner which is obtainedin ayield'o'f"78% of theory, mean intrinsic viscosity of 1.701

Example-IX 3.8 parts by weight of tetrar'nethylene diamine (OLI mOIS') and '54 parts by Weight 'of ethylene diamine (0L9 mols) are dissolved in 1000 parts by Weight of water containing 159partS by Weight of sodium carbonate (50% mol) excess and-30 parts by weight of asouiumiauryl sulfate emulsifying agent {30% strength). 215 parts by weight of 1.4-

.butanediolbis chloroforniate are dissolved in 900 as a high-speed stirrer so as to effect strong agitation, the aqueous solution being introduced into the reactor at a rate of 80 volumes per minute and the toluene solution being introduced at a rate of 87 volumes per minute. Polymerization with the formation of a mixed 2,4 and 4,4-polyurethane takes place immediately as the separate solutions are brought together and polymer formed precipitates from solution. The resulting reaction mixture is withdrawn from the reaction zone at the same time at which the fresh solutions are introduced, the polymer separated by filtration, washed with water to remove occluded inorganic salts and dried. The yield of mixed polyurethane obtained is 84% of theory and the polymer thus formed has an intrinsic viscosity 'of 1.25.

Example X 30 parts by weight of titanium dioxide are milled in a ball mill for 24 hours with 300 parts by weight of water and 2 parts by weight of a 30 aqueous solution of sodium lauryl sulfate (30% strength). 2.7 parts by weight of this titanium dioxide concentrate are added to 1800 parts by weight of water to form a dispersion. A polymer is formed following the procedure of Example IV with 150 volumes per minute of the titanium dioxide dispersion being added to the reactor as a third component, together. with the diamine and bis-chloroformate. A pigmented polymer having an intrinsic viscosity of 1.38 is obtained in a yield of 88%. The pigmented polymer may be readily melt-spun into filaments and the pigment seems to facilitate the spinning operation.

Example XI 30 parts by weight of Franconia blue (a phthalocyanine blue pigment) are milled for 24 hours in a ball mill with 300 parts by weight of water containing 2 parts by weight of a 30% solution of sodium lauryl sulfate (30% strength). 2.2 parts by weight of this pigment concentrate are added to 1800 parts by weight of water to form an aqueous pigment dispersion. This dispersion is employed in forming a polymer in the manner described in Example X, 150 volumes per minute of the blue pigment dispersion being added as a third component in forming the polymer in place of the titanium dioxide dispersion employed therein. A blue polymer having an intrinsic viscosity of 1.4 is obtained in a yield of 86% of theory. The polymer may be molded or spun into uniformly colored articles or filaments.

Example XII 88 parts by weight of tetramethylene diamine are dissolved in 1000 parts by weight of Water containing 88 parts by Weight of sodium hydroxide and parts by weight of sodium lauryl sulfate (30% strength). 215 parts by weight of 1,4- butanediol bis-chloroformate are dissolved in 900 parts by weight of toluene'and both solutions are separately cooled to a temperature of C. The cooled solutions are then introduced into a reactor having agitating means and containing 500 volumes of free reactor space, the solutions each being added at a rate of 150 volumes per minute. The reaction mixture formed is thoroughly agitated in the reaction zone and is withdrawn, together with the polymer formed, at a rate equal to that at which the solutions are introduced. The polymer formed is obtained in a yield of 81% of theory and has an intrinsic viscosity of 0.93.

n is to be un erstood'that the foregoing .de-'

. 10 l tailed description is given merely by way of illustrationand that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. Process for the production of polyurethanes, which comprises continuously introducing into a reaction zone an organic solvent solution of at least one bis-chloroformate free from reactive groups other than the chloroformate groups, an aqueous solution of a polyamine free from reactive groups other than the amino groups and an alkaline agent, effecting a polymerization reaction in said zone by continuously and strongly agitating the mixture therein, and continuously withdrawing a slurry of polyurethane polymer from said reaction zone at a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, the said solutions being passed through said reaction zone at a rate such that the reactants remain in said zone for a period of less than about 10 minutes and the degree of stirring and the period of time the reactants remain in said reaction zone being sufficient to cause a substantially complete polymerization during the passage of the reactants through said zone.

2. Process for the production of polyurethanes, which comprises continuously introducing into a reaction zone a water-immiscible organic solvent solution of at least one bis-chloroformate free from reactive groups other than the chloroformate groups, an aqueous solution of a polyamine free from reactive groups other than the amino groups and having a free amino hydrogen on at least two amino groups and an alkaline agent, effecting a polymerization reaction in said zone by continuously and strongly agitating the mixture therein, and continuously withdrawing a slurry of polyurethane polymer from said reaction zone at a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, the said solutions being passed through said reaction zone at a rate such that the reactants remain in said zone for a period of less than about 10 minutes andthe degree of stirring and the period of time the reactants remain in said reaction zone being sufficient to cause a substantially complete polymerization during the passage of the reactants through said zone.

3. Process for the production of polyurethanes, which comprises continuously introducing into a reaction zone a water-immiscible organic solvent solution of at least one bis-chloroformate free from reactive groups other than the chloroformate groups, an aqueous solution of a polyamine free from reactive groups other than the amino groups and having a free amino hydrogen on at least two amino groups, an emulsifying agent and an alkaline agent, effecting a polymerization reaction in said zone by continuously and strongly agitating the mixture therein, and continuously withdrawing a slurry of polyurethane polymer from said reactionzone at a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, the said solutions being passed through the reaction zone at a rate such that:

the reactants remain in said zone for a period of between about 0.3 and 3.0 minutes and the degree of stirring in said reaction zone being suflicient to cause a substantially complete'polymerization during the passage of the reactants through said zone.

4. Process for the production of polyurethanes,

which comprises continuously introducing into a from reactive groups other than the chlorofor- .mate groups, an aqueous solution of a polyamine free from reactive groups other than the amino groups and havinga freeamino hydrogen on at least'two amino groups, an emulsifying agent and an-alkaline agent, effecting a polymerization reaction in said zone by continuously and strongly agitating the mixturetherein, and continuously withdrawing a slurry of polyurethane polymer from said reaction zone at a volumetric rate equal to the volumetric rateat which the solutions are introduced therein, the said solutions being .passed through said reaction zone at a rate such that the reactants remain in said zone for a period-of less than about 3 minutes, and the degree ofstirring-and the period of time the reactants remain in said reaction zone .being sufficient to cause .a substantially complete polymerization during the passage of the reactants through said zone.

5. Process for the production of .polyurethanes, whichcomprises continuously introducing into a reaction zone an organic solvent solution of at least one bis-chloroiormate free from reactive groups other than the chloroformate groups and having aconcentration of between about 0.2 to 1.5 moles per liter, .an aqueous solution of .a polyamine free from reactive'groups other than the amino groups and having a free amino hydrogen on at least two amino groups and having a concentration of between about 0.2 to 1.5 moles per liter and an alkalineagent, efiecting a polymerization reaction in said zone by continuously and strongly agitating the mixture therein, and continuously withdrawing a slurry of polyurethane polymer from said reaction zone at a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, the said solutions being passed through said reaction zone at a rate such that the reactants remain in said zone for a periodof less than about minutes and the degree of stirring and the period of time the reactants remain in said reactionzone being suflicient to cause a substantially complete polymerization during the passage of the reactants through said zone.

6. Process for the production of polyurethanes, which comprises continuously introducing into a reaction zone maintained at a temperature of between about 10 C. and 35 C. an organic solvent solution of at least one bis-chloroformate free from reactive groups other than the chloroiormate groups, an aqueous solution of a polyamine free from reactive groups other than the amino groups and having a free amino hydrogen on at least two amino groups and an alkaline agent, effecting a polymerization reaction in said zone by continuously and strongly agitating the mixture therein, and continuously withdrawing a slurry of polyurethane polymer from said reaction zone at a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, the said solutions being passed through said reaction zone at a rate such that the reactants remain in said zone for a period of less than about 10 minutes and the degree of stirring and the period of time the reactants remain in said reaction zone being suflicient to cause a substantially complete polymerization during the passage of the reactants through said zone.

7. Process for the production of polyurethane,

reaction zone :an organic solvent solution of at least one bis-chloroformate free from reactive groups other than the chloroformate groups, an aqueous solution of a-polyaminerree from reactive groups other than the .amino groups and having a free amino hydrogen on at least two amino groups and upto about a molar excess of an alkalineagenh'effecting a polymerization reactionin said zone by continuously and strongly agitating the mixturetherein, and continuously withdrawing a slurry of polyurethane polymer from said reaction zone atv a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, thesaid solutions being passed through said reaction zone .at a rate such that the reactants remain in-said zone for a period of less than about 10 minutes and the degree of stirring and the period of time the reactants remain in said reaction zone being sufiicient to cause :a substantially complete polymerization during thepassageof the reactants through said zone.

8. Process for the production of polyurethanes, which comprises continuously introducing into a reaction zone maintained at a temperature of between about l0 and 35 C. a water-immiscible organic solvent solution of at least one bis-chloroformate free from reactive groups other than the ,chloroformate groups, .an aqueous solution of a polyamine free from reactive groups other than the amino groups and having a free amino hydrogen on at least two amino groups, an emulsifying agent and up to about-a 75% molar excess of an alkaline agent, efiecting a polymerization reaction-in saidzone by continuously and strongly agitating the mixture therein, and continuously withdrawing a slurry of polyurethane polymer from said reaction zone at a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, the said solutions being passed throughsaid reaction zone at a rate such that the reactants remain in'said zone for a period of between about 0.3 and 3.0 minutes and the degree of stirring in :said reaction zone being sufiicient to-cause asubstantially complete polymerization during the passage of the reactants through said zone.

9. Process for the production of polyurethanes, which comprises continuously introducing into a reaction zone an organic solvent solution of at least one bis-chloroformate free from reactive groups other than the chloroiormate groups, an aqueous solution of a polyamine free from reactive groups other than the amino groups and having a free amino hydrogen on at least two amino groups, a pigment and an alkaline agent, efiecting a polymerizationreaction in said zone by continuously and strongly agitating the mixture therein, and continuously withdrawing a slurry of polyurethane polymer .from said reaction zone at a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, the said solutions being passed through said reaction zone at a rate such that the reactants remain in said zone for a period of less than about 10 minutes and the degree of stirring and the period of time the reactants remain in said reaction zone being sufficient to cause a substantially complete polymerization during the passage of the reactants through said zone.

10. Process for the production of polyurethanes, which comprises continuously introducing into a reaction zone a water-immiscible organic solvent solution of at least one polyalkylene bis-chlorowhich comprises continuously introducing into a 7 iormate .frce from reactive groups other than the chloroiormate groups, an aqueous solution of a polyalkylene polyamine free from reactive groups other than the amino groups and having a free amino hydrogen on at least two amino groups, an emulsifying agent and an alkaline agent, effecting a polymerization reaction in said zone by continuously and strongly agitating the mixture therein, and continuously withdrawing a slurry of polyurethane polymer from said reaction zone at a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, the said solutions being passed through said reaction zone at a rate such that the reactants remain in said zone for a period of less than about 3 minutes and the degree of stirring and the period of time the reactants remain in said reaction zone being sufiicient to cause a substantially complete polymerization during the passage of the reactants through said zone.

11. Process for the production of 4,4-polyurethane which comprises continuously introducing into a reaction zone an organic solvent solution of 1,4-butanediol bis-chloroformate, an aqueous solution of tetramethylene diamine and an alkaline agent, effecting a polymerization reaction in said zone by continuously and strongly agitating the mixture therein, and continuously withdrawing a slurry of polyurethane polymer from said reaction zone at a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, the said solutions being passed through said reaction zone at a rate such that the reactants remain in said zone for a period of less than about minutes and the degree of stirring and the period of time the reactants remain in said reaction zone being sumcient to cause a substantially complete polymerization during the passage of the reactants through said zone.

12. Process for the production of 4,4-polyurethane which comprises continuously introducing into a reaction zone maintained at a temperature of between about 10 and C. a water-immiscible organic solvent solution of 1,4- butanediol bis-chloroformate, an aqueous solution of tetramethylene diamine, an emulsifying agent and up to about a molar excess of an alkaline agent, efiecting a polymerization reaction in said zone by continuously and strongly agitating the mixture therein, and continuously withdrawing a slurry of polyurethane polymer from said reaction zone at a volumetric rate equal to the volumetric rate at which the solutions are introduced therein, the said solutions being passed through said reaction zone at a rate such that the reactants remain in said zone for a period of between about 0.3 to 3.0 minutes and the degree of stirring in said reaction zone being suflicient to cause a substantially complete polymerization during the passage of the reactants through said zone.

JACK SWERDLOFF. SAMUEL B. McFARLANE.

References Cited in the file of this patent UNITED STATES PATENTS (first addition to No. 892,361 

1. PROCESS FOR THE PRODUCTION OF POLYURETHANES, WHICH COMPRISES CONTINUOUSLY INTRODUCING INTO A REACTION ZONE AN ORGANIC SOLVENT SOLUTION OF AT LEAST ONE BIS-CHLOROFORMATE FREE FROM REACTIVE GROUPS OTHER THAN THE CHLOROFORMATE GROUPS, AN AQUEOUS SOLUTION OF A POLYAMINE FREE FROM REACTIVE GROUPS OTHER THAN THE AMINO GROUPS AND AN ALKALINE AGENT, EFFECTING A POLYMERIZATION REACTION IN SAID ZONE BY CONTINUOUSLY AND STRONGLY AGITATING THE MIXTURE THEREIN, AND CONTINUOUSLY WITHDRAWING A SLURRY OF POLYURETHANE POLYMER FROM SAID REACTION ZONE AT A VOLUMETRIC RATE EQUAL TO THE VOLUMETRIC RATE AT WHICH THE SOLUTIONS ARE INTRODUCED THEREIN, THE SAID SOLUTIONS BEING PASSED THROUGH SAID REACTION ZONE AT A RATE SUCH THAT THE REACTANTS REMAINS IN SAID ZONE FOR A PERIOD OF LESS THAN ABOUT 10 MINUTES AND THE DEGREE OF STIRRING AND THE PERIOD OF TIME THE REACTANTS REMAIN IN SAID REACTION ZONE BEING SUFFICIENT TO CAUSE A SUBSTANTIALLY COMPLETE POLYMERTHROUGH SAID ZONE. 